To me the appeal of open world content in this game is having something to do other than dungeons and also having the freedom to do things with however many people you want, and not the required 4/8/24 person setup of instanced dungeons and battles.

The type of open world content I would love to see in XIV is where we adventurers would have to fight off forces attempting to breach a city, camp, or keep. In FFXI, it was fun defending the cities or kingdoms. It wasn't about claiming things first or even the rewards, necessarily. Everyone in the zone had a common goal, which was to protect the city. There should be waves of enemies coming in, with the weakest first and a unique boss (or even multiple bosses) last. It should be a struggle. In these battles, it would bring an opportunity for us to fight alongside our favorite NPCs, and alongside our fellow adventurers.

I guess this would qualify as a lag fest, but it would be worth it if it were fun.